<html>
  <head>
    <meta charset="utf-8" />
    <title>www.husonghe.com</title>
    <style>
      html {
        height: 100%;
        background-image: -webkit-radial-gradient(
          ellipse farthest-corner at center center,
          #1b44e4 0%,
          #020f3a 100%
        );
        background-image: radial-gradient(
          ellipse farthest-corner at center center,
          #1b44e4 0%,
          #020f3a 100%
        );
        cursor: move;
      }

      body {
        width: 100%;
        margin: 0;
        overflow: hidden;
      }
      /* canvas {
        width: 5760px;
        height: 2169px;
      } */
    </style>
  </head>

  <body>
    <canvas id="canv" width="1920" height="572"></canvas>
    <script>
      var num = 200;
      var w = window.innerWidth;
      var h = window.innerHeight;
      var max = 100;
      var _x = 0;
      var _y = 0;
      var _z = 150;
      var dtr = function (d) {
        return (d * Math.PI) / 180;
      };

      var rnd = function () {
        return Math.sin((Math.floor(Math.random() * 360) * Math.PI) / 180);
      };
      var dist = function (p1, p2, p3) {
        return Math.sqrt(
          Math.pow(p2.x - p1.x, 2) +
            Math.pow(p2.y - p1.y, 2) +
            Math.pow(p2.z - p1.z, 2)
        );
      };

      var cam = {
        obj: {
          x: _x,
          y: _y,
          z: _z,
        },
        dest: {
          x: 0,
          y: 0,
          z: 1,
        },
        dist: {
          x: 0,
          y: 0,
          z: 200,
        },
        ang: {
          cplane: 0,
          splane: 0,
          ctheta: 0,
          stheta: 0,
        },
        zoom: 1,
        disp: {
          x: w / 2,
          y: h / 2,
          z: 0,
        },
        upd: function () {
          cam.dist.x = cam.dest.x - cam.obj.x;
          cam.dist.y = cam.dest.y - cam.obj.y;
          cam.dist.z = cam.dest.z - cam.obj.z;
          cam.ang.cplane =
            -cam.dist.z /
            Math.sqrt(cam.dist.x * cam.dist.x + cam.dist.z * cam.dist.z);
          cam.ang.splane =
            cam.dist.x /
            Math.sqrt(cam.dist.x * cam.dist.x + cam.dist.z * cam.dist.z);
          cam.ang.ctheta =
            Math.sqrt(cam.dist.x * cam.dist.x + cam.dist.z * cam.dist.z) /
            Math.sqrt(
              cam.dist.x * cam.dist.x +
                cam.dist.y * cam.dist.y +
                cam.dist.z * cam.dist.z
            );
          cam.ang.stheta =
            -cam.dist.y /
            Math.sqrt(
              cam.dist.x * cam.dist.x +
                cam.dist.y * cam.dist.y +
                cam.dist.z * cam.dist.z
            );
        },
      };

      var trans = {
        parts: {
          sz: function (p, sz) {
            return {
              x: p.x * sz.x,
              y: p.y * sz.y,
              z: p.z * sz.z,
            };
          },
          rot: {
            x: function (p, rot) {
              return {
                x: p.x,
                y: p.y * Math.cos(dtr(rot.x)) - p.z * Math.sin(dtr(rot.x)),
                z: p.y * Math.sin(dtr(rot.x)) + p.z * Math.cos(dtr(rot.x)),
              };
            },
            y: function (p, rot) {
              return {
                x: p.x * Math.cos(dtr(rot.y)) + p.z * Math.sin(dtr(rot.y)),
                y: p.y,
                z: -p.x * Math.sin(dtr(rot.y)) + p.z * Math.cos(dtr(rot.y)),
              };
            },
            z: function (p, rot) {
              return {
                x: p.x * Math.cos(dtr(rot.z)) - p.y * Math.sin(dtr(rot.z)),
                y: p.x * Math.sin(dtr(rot.z)) + p.y * Math.cos(dtr(rot.z)),
                z: p.z,
              };
            },
          },
          pos: function (p, pos) {
            return {
              x: p.x + pos.x,
              y: p.y + pos.y,
              z: p.z + pos.z,
            };
          },
        },
        pov: {
          plane: function (p) {
            return {
              x: p.x * cam.ang.cplane + p.z * cam.ang.splane,
              y: p.y,
              z: p.x * -cam.ang.splane + p.z * cam.ang.cplane,
            };
          },
          theta: function (p) {
            return {
              x: p.x,
              y: p.y * cam.ang.ctheta - p.z * cam.ang.stheta,
              z: p.y * cam.ang.stheta + p.z * cam.ang.ctheta,
            };
          },
          set: function (p) {
            return {
              x: p.x - cam.obj.x,
              y: p.y - cam.obj.y,
              z: p.z - cam.obj.z,
            };
          },
        },
        persp: function (p) {
          return {
            x: ((p.x * cam.dist.z) / p.z) * cam.zoom,
            y: ((p.y * cam.dist.z) / p.z) * cam.zoom,
            z: p.z * cam.zoom,
            p: cam.dist.z / p.z,
          };
        },
        disp: function (p, disp) {
          return {
            x: p.x + disp.x,
            y: -p.y + disp.y,
            z: p.z + disp.z,
            p: p.p,
          };
        },
        steps: function (_obj_, sz, rot, pos, disp) {
          var _args = trans.parts.sz(_obj_, sz);
          _args = trans.parts.rot.x(_args, rot);
          _args = trans.parts.rot.y(_args, rot);
          _args = trans.parts.rot.z(_args, rot);
          _args = trans.parts.pos(_args, pos);
          _args = trans.pov.plane(_args);
          _args = trans.pov.theta(_args);
          _args = trans.pov.set(_args);
          _args = trans.persp(_args);
          _args = trans.disp(_args, disp);
          return _args;
        },
      };

      (function () {
        "use strict";
        var threeD = function (param) {
          this.transIn = {};
          this.transOut = {};
          this.transIn.vtx = param.vtx;
          this.transIn.sz = param.sz;
          this.transIn.rot = param.rot;
          this.transIn.pos = param.pos;
        };

        threeD.prototype.vupd = function () {
          this.transOut = trans.steps(
            this.transIn.vtx,
            this.transIn.sz,
            this.transIn.rot,
            this.transIn.pos,
            cam.disp
          );
        };

        var Build = function () {
          this.vel = 0.04;
          this.lim = 360;
          this.diff = 200;
          this.initPos = 100;
          this.toX = _x;
          this.toY = _y;
          this.go();
        };

        Build.prototype.go = function () {
          this.canvas = document.getElementById("canv");
          this.canvas.width = window.innerWidth;
          this.canvas.height = window.innerHeight;
          this.$ = canv.getContext("2d");
          this.$.globalCompositeOperation = "source-over";
          this.varr = [];
          this.dist = [];
          this.calc = [];

          for (var i = 0, len = num; i < len; i++) {
            this.add();
          }

          this.rotObj = {
            x: 0,
            y: 0,
            z: 0,
          };
          this.objSz = {
            x: w / 5,
            y: h / 5,
            z: w / 5,
          };
        };

        Build.prototype.add = function () {
          this.varr.push(
            new threeD({
              vtx: {
                x: rnd(),
                y: rnd(),
                z: rnd(),
              },
              sz: {
                x: 0,
                y: 0,
                z: 0,
              },
              rot: {
                x: 20,
                y: -20,
                z: 0,
              },
              pos: {
                x: this.diff * Math.sin((360 * Math.random() * Math.PI) / 180),
                y: this.diff * Math.sin((360 * Math.random() * Math.PI) / 180),
                z: this.diff * Math.sin((360 * Math.random() * Math.PI) / 180),
              },
            })
          );
          this.calc.push({
            x: 360 * Math.random(),
            y: 360 * Math.random(),
            z: 360 * Math.random(),
          });
        };

        Build.prototype.upd = function () {
          cam.obj.x += (this.toX - cam.obj.x) * 0.05;
          cam.obj.y += (this.toY - cam.obj.y) * 0.05;
        };

        Build.prototype.draw = function () {
          this.$.clearRect(0, 0, this.canvas.width, this.canvas.height);
          cam.upd();
          this.rotObj.x += 0.1;
          this.rotObj.y += 0.1;
          this.rotObj.z += 0.1;

          for (var i = 0; i < this.varr.length; i++) {
            for (var val in this.calc[i]) {
              if (this.calc[i].hasOwnProperty(val)) {
                this.calc[i][val] += this.vel;
                if (this.calc[i][val] > this.lim) this.calc[i][val] = 0;
              }
            }

            this.varr[i].transIn.pos = {
              x: this.diff * Math.cos((this.calc[i].x * Math.PI) / 180),
              y: this.diff * Math.sin((this.calc[i].y * Math.PI) / 180),
              z: this.diff * Math.sin((this.calc[i].z * Math.PI) / 180),
            };
            this.varr[i].transIn.rot = this.rotObj;
            this.varr[i].transIn.sz = this.objSz;
            this.varr[i].vupd();
            if (this.varr[i].transOut.p < 0) continue;
            var g = this.$.createRadialGradient(
              this.varr[i].transOut.x,
              this.varr[i].transOut.y,
              this.varr[i].transOut.p,
              this.varr[i].transOut.x,
              this.varr[i].transOut.y,
              this.varr[i].transOut.p * 2
            );
            this.$.globalCompositeOperation = "lighter";
            g.addColorStop(0, "hsla(255, 255%, 255%, 1)");
            g.addColorStop(0.5, "hsla(" + (i + 2) + ",85%, 40%,1)");
            g.addColorStop(1, "hsla(" + i + ",85%, 40%,.5)");
            this.$.fillStyle = g;
            this.$.beginPath();
            this.$.arc(
              this.varr[i].transOut.x,
              this.varr[i].transOut.y,
              this.varr[i].transOut.p * 2,
              0,
              Math.PI * 2,
              false
            );
            this.$.fill();
            this.$.closePath();
          }
        };
        Build.prototype.anim = function () {
          window.requestAnimationFrame = (function () {
            return (
              window.requestAnimationFrame ||
              function (callback, element) {
                window.setTimeout(callback, 1000 / 60);
              }
            );
          })();
          var anim = function () {
            this.upd();
            this.draw();
            window.requestAnimationFrame(anim);
          }.bind(this);
          window.requestAnimationFrame(anim);
        };

        Build.prototype.run = function () {
          this.anim();

          window.addEventListener(
            "mousemove",
            function (e) {
              this.toX = (e.clientX - this.canvas.width / 2) * -0.8;
              this.toY = (e.clientY - this.canvas.height / 2) * 0.8;
            }.bind(this)
          );
          window.addEventListener(
            "touchmove",
            function (e) {
              e.preventDefault();
              this.toX = (e.touches[0].clientX - this.canvas.width / 2) * -0.8;
              this.toY = (e.touches[0].clientY - this.canvas.height / 2) * 0.8;
            }.bind(this)
          );
          window.addEventListener(
            "mousedown",
            function (e) {
              for (var i = 0; i < 100; i++) {
                this.add();
              }
            }.bind(this)
          );
          window.addEventListener(
            "touchstart",
            function (e) {
              e.preventDefault();
              for (var i = 0; i < 100; i++) {
                this.add();
              }
            }.bind(this)
          );
        };
        var app = new Build();
        app.run();
      })();
      window.addEventListener(
        "resize",
        function () {
          canvas.width = w = window.innerWidth;
          canvas.height = h = window.innerHeight;
        },
        false
      );
    </script>
  </body>
</html>
